Effect of different food and sugar sources on the larval biology and adult longevity of Anopheles darlingi (Diptera: Culicidae)

Anopheles darlingi is the main vector of the disease in the Amazon, and several studies on its ecology and behavior have been conducted. Although the basic nutritional requirements of insects are well known, quantitative needs with respect to food components and their balance vary among insect species; therefore, such information is needed in order to improve insect rearing for mass production. The present work evaluated the effect of different animal diets on larval biology and the utilization of different sugar sources in An. darlingi adults. First instar larvae obtained from wild-captured mosquitoes were reared in plastic trays containing 1 L of water and fed daily according to their larval instar stage with different commercial diets for fish, reptiles, and dogs, as well as a manipulated diet including Macapo. Larval mortality was recorded daily, and development time was calculated as the time required for 50% of the larvae to reach the last larval instar. Pupae and adults produced from larvae fed with different animal diets were also counted daily. Adults were fed with 10% sugar solutions of honey, sucrose, and sugar cane molasses, and longevity was recorded. Larval mortality was reduced for larvae feeding on fish food (higher protein content) compared to those fed with dog food (lower protein content) in later instars; the first and third instars presented a higher mortality than other instars, regardless of the food provided. Larval development time was reduced in larvae fed with fish food compared with dog food. The average daily production of pupae and adults were significantly higher in the treatment using fish food than in all other diet treatments. In general, adults from larvae fed on fish food and those that ingested honey as an adult sugar source lived longer than those reared on other treatments. Fish food, i.e., Tetramin Tropical Flakes, for larvae and honey, as a carbohydrate source for adults, seem to better support the rearing of Anopheles darlingi under our experimental conditions.

Evaluation of attractive toxic sugar baits (ATSB) against Aedes aegypti (Diptera: Culicidae) in laboratory

Toxic baits, widely used against insect pests, are being successfully used to control mosquito vectors. In the present study, basic aspects for Attractive Toxic Sugar Baits (ATSBs) use as a control tool against Aedes aegypti including insecticide dosage, bait composition and plant application under laboratory conditions were evaluated. The Lethal Concentrations (LC 50 and 90) of boric acid (insecticide) Ae. aegypti engorgement and mortality were determined using ATSBs prepared using fruits (guava, mango and cupuaçu) and offered to mosquitoes on cotton discs and also sprayed on a Kalanchoe blossfeldiana plant. LCs of Ae. aegypti males and females did not differ significantly and varied from 0.53 to 2.46%, decreasing from 24 to 48 hours. No significant difference in the proportion of engorged male mosquitoes in ATSB (0.60) and Attractive Sugar Bait (ASB) (0.65) was found, but females engorged more on ASB (control bait) (0.80) compared to ATSBs (0.67). General mortality rate of mosquitoes in ATSB and ASB were 0.81 and 0.10 for males, respectively; 0.61 and 0.12 for females, respectively. Fruit composition affected neither engorgement nor mortality. ATSB applied on plants caused the mortality of males and females ranging from 0.75-0.87 while mortality on ASB sprayed plants varied from 0.07-0.14. Different common fruit juices and a low toxic oral insecticide are readily accepted, engorged and causes a high mortality both males and females Ae. aegypti using ATSBs. Moreover, the use of a common indoor plant in the region sprayed with ATSB under laboratory conditions leads to significant mosquito mortality.

The genome of Anopheles darlingi, the main neotropical malaria vector

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vector–human and vector–parasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles-darlingi.